Window-sash lock.



C. A.'NELSON.

WINDOW SASH LQCK.

APPLICATION FILED OCT. 7. I915.

' Patented Sept 5, 1916.

CHARLES A NELSON, OF CHICAGO, ILLINOIS, ASSIGNOR T0 0. A. NELSON 00., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINQIS,

wInDow-sAsH' LOCK.

mamas.

To all whom it may concern:

Beit known that I, CHARLES A. NELSON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Window-Sash Locks, of which the following is a specification.-

This invention relates to improvements in window sash locks, and has for its salient objects, to provide a lock which is of comparatively simple and inexpensive construction and which is so organized that any attempt to open the sash which it controls will result in a more sure and effective locking of the parts against movement; to provide a device of the character referred to which may be released only by the use of a key, so that unauthorized tampering with the sash lock is obviated; to provide a construction in which the key which serves to unlock the device may be used for' holding the device in unlocked position; to provide a device which may be conveniently applied, and which cooperates with a locking-plate in such manner that mutilation of the sash proper is avoided; and, in general, to provide a simple and improved device of the character referred to.

The invention will be readily understood from the following description, reference being had to the accompanying drawings, in which- Figure 1 is a view showing the device applied to an ordinary window sash so as to lock the sash to which it is applied and the companion sash together; Fig. 2 is an elevation of the parts shown in Fig. 1; Fig. 3 is a top or plan view of the sash lock applied, parts of the sash and casing being shown in section; Fig. I is a transverse vertical sectional view through the casing in a plane coincident with the axis of the locking cam;

the locking cam and actuating'snring being,

- however, shown in-elevation; Fig. 5 is a sectional View taken at right angles to that of Fig. 4, the locking cam, its hub, and the actuating spring, being shown in side elevation.

In the approved embodiment of my invention, shown in the drawings, 1 designates as v a whole a casing, referably, and as shown taking the form 0 a hollow casting adapted to house and support an oscillatory locking Cam 2 and its actuating spring 3. The cas- -Speciflcation of Letters Patent.

Application filed October 7, 1915. Serial No. 54,485.

web portion 2". ing portion of the periphery of the locking Patented Septfi, lmlfi.

- which the cam 2 is fixed, while the opposite side of the casing is provided with a hub 8 alined with the bearing aperture 6 and .receiving the enlarged hub bearing 9 of the rock shaft. The aperture through the cam 2, which receives the rock shaft, is squared, as indicated in dotted lines at 10 (Fig. 5), and that part of the rock shaft which occupies this aperture is squared to correspond. The extremity of the rock shaft' which lies within the hollow hub 8 is cut away at each side to produce a projecting web 11 which preferably takes the form of two narrow integral segments of the shaft, as seen clearly in Fig. 5; this projection 11 forming the bit which is straddled and engaged by the forked end of a key 12, as seen clearly in Fig. 4. The locking cam 2 is segmental in side elevation, has a central hub portion 2', in which is the squared aperture as hereinbefore described, has a relatively wide peripheral portion 2 and a central The operative or contactcam is suitably roughened to insure positive engagement, with an opposed face-plate 13; both the face of the face-plate and the periphery of the cam being desirably trans versely corrugated, as indicated at 14 and 15, to insure such positive engagement. The

. periphery of the cam is eccentric or spirally formed relatively to its axis of oscillation; its lower and forward part, as viewed in Fig. 5 being of smallest radius and increasing in radius from this point around to its rear portion or heel. In order to force the cam forwardly under a constant but yield- V cam.

modate and and rests on the base-plate-within the housing at a point remote from the hub of the As an improved detail of construction Which enables me to readily engage, these sash looks with a, wide variety of keys and cotiperative barrels which will insure individuality as between the several sash locks and their keys, I provide separately constructed barrels and barrel housings adapted to be rigidly and permanently secured to any given sash lock casing. Describing this detail, 17 designates an outer cylindrical thimble or casing, which is closed as to its outer end except for a suitable circular key opening 17, and which at its inner end is suitably upset or otherwise rigidly secured within a rabbet 18 formed in the hub 8 of the casing. Inside this casing 17 I-rigidly secure one or more barrels, as 19 and 20,

each of which barrels is closed at its outer end except for a key slot therein, and register with each other and with the outer casing 17. The key 12 is provided with notches to register with the key-slots of the barrels,

round as to their middle portions to accompermit the rotation of the key, in

the usual manner. Moreover, the fit of the key within the barrels is purposely madesomewhat loose so that the key may be defiected out of exact alinement with the axis of the look while inserted. In the perimeter of the key aperture 17 of the casing 17, I provide a notch 21 (see Fig. 1) which is adapted to receive the edge of the key when it has been rotated into register therewith and deflected so as to enter said notch: said notch 21 being so located with reference to the peri herv of the locking cam and the normal entrance position of the key, that the parts, when inter-engaged,will hold the cam back or in unlocked positionz'. e., free from engagement withtheface-plate 13.

The operation of the device will be clear from the foregoing description of its construction, but may be briefly recapitulated. The parts being applied to the sash, the latter may be closed without manipulating the it being understood that the latter slots'are somewhat modified without tending to turn said cam,

' in condition to be opened or closed freely,

the key is left in its socket and engaged at its edge with the notch 21, thus holding the locking cam in inoperative position. Since each sash lock is intended tobe provided with a differently proportioned key and key .barrels, the sash lock cannot be tampered .with except by its own key or a duplicate.

It will, of course, be obvious that the.

details of construction of the lockmay be departing from the invention, especially as set forth in the broader of the appended claims.

I .claim as my invention: 1 1. In'a window locking device, a casing,

a shaft extending through said casing, said shaft having a square portion intermediate its ends, a cam secured to said square portion of the shaft, a spring within the casing and secured to the cam normally part of the periphery of said cam, a face plate having corrugations adapted to mesh with the corrugations of the cam by means of the spring, a web on one end of said shaft, and a key adapted to engage said web to turn the cam.

- 2. In a'window locking device, a casing secured to one sash, a shaft extending through said casing and having a square portion thereon, a said shaft, a spring having one end secured to said cam, a corrugated face plate secured to the other sash, a key adapted to engage one end of the shaft to turn the cam into unlocked position, and means for holding said cam in unlocked position.

3. In a window locking device, a casing secured to one sash, a shaft extending through/said casing and having a square portion thereon, a corrugated cam fixed to said shaft, a corrugated face plate secured to the other sash, a spring within the casing having one end secured to'said cam and normally tending to force the cam into engagement with the face plate to prevent the sashes from moving with respect to each corrugated cam fixed to.

corrugations on other, a ke', adapted to engage said shaft to turn the cam into unlocked position, and means associated with the'key and the casing for holding said cam in unlocked posi- 

